Study of wetting reaction between eutectic AuSn and Au foil

Wetting reactions between eutectic AuSn solder and Au foil have been studied. During the reflow process, Au foil dissolution occurred at the interface of AuSn/Au, which increases with temperature and time. The activation energy for Au dissolution in molten AuSn solder is determined to be 41.7 kJ/mol. Au₅Sn is the dominant interfacial compound phase formed at the interface. The activation energy for the growth of interfacial Au₅Sn phase layer is obtained to be 54.3 kJ/mol over the temperature range 360–440°C. The best wettability of molten AuSn solder balls on Au foils occurred at 390°C (wetting angle is about 25°). Above 390°C, the higher solder oxidation rate retarded the wetting of the molten AuSn solder.     

阳极铝箔交流腐蚀发孔对比容的影响

采用５０Ｈｚ交流电腐蚀发孔和进一步腐蚀阳极铝箔，在腐蚀箔表面形成透明钝化型腐蚀膜且蚀孔孔径较大。在交流电腐蚀过程中不产生发黑、掉粉和减薄现象。另外，该工艺对盐酸浓度和硫酸添加剂浓度的适应范围很宽。     

Growth and surface characterization of sputter-deposited molybdenum oxide thin films

Molybdenum oxide thin films were produced by magnetron sputtering using a molybdenum (Mo) target. The sputtering was performed in a reactive atmosphere of an argon-oxygen gas mixture under varying conditions of substrate temperature (T_s) and oxygen partial pressure (pO₂). The effect of T_s and pO₂ on the growth and microstructure of molybdenum oxide films was examined in detail using reflection high-energy electron diffraction (RHEED), Rutherford backscattering spectrometry (RBS), energy-dispersive X-ray spectrometry (EDS), X-ray photoelectron spectroscopy (XPS), and scanning electron microscopy (SEM) measurements. The analyses indicate that the effect of T_s and pO₂ on the microstructure and phase of the grown molybdenum oxide thin films is remarkable. RHEED and RBS results indicate that the films grown at 445 °C under 62.3% O₂ pressure were stoichiometric and polycrystalline MoO₃. Films grown at lower pO₂ were non-stoichiometric MoO_x films with the presence of secondary phase. The microstructure of the grown Mo oxide films is discussed and conditions were optimized to produce phase pure, stoichiometric, and highly textured polycrystalline MoO₃ films.     

Characterization of sputtered Ta-C-N film in the Cu/barrier/Si contact system

Characterization of sputtered tantalum carbon nitride (Ta-C-N) film in Cu/barrier/Si system was reported for the first time. With a 50∶50 wt.% TaC target and an optimum N₂/Ar flow rate (in sccm) ratio of 2/24, a 600 Å-thick sputtered Ta-C-N layer was shown metallurgically stable up to 650°C annealing for 30 min, which is about 100°C higher as compared to the case without nitrogen doping. Cu diffusion through the local defects or grain boundaries of the Ta-C-N barrier layer into Si substrate is the dominant factor responsible for the failure of the Ta-C-N barrier layer after high temperature annealing.     

浅谈电解铜箔生产企业的产品品质意识

文章简述了品质意识对产品品质的重要性和从七个方面强化电解铜箔生产企业产品品质意识。     

电解铜箔中异常粒子成长的解析

研究了电解铜箔制造时旨在防止缺陷的镀铜层上发生的异常粒子成长。在Ti基板上形成镀铜层,应用配备有能量耗散x一线分光计的电子扫描显微镜（SEM-EDX）和x一线衍射观察异常粒子析出。异常粒子的发生取决于Ti基材预处理方法。预处理加工时机械抛光发生的Ti粒子与异常粒子成长有关。Ti粒子附近的铜的取向不同于其它部分的镀层。因此Ti粒子与异常粒子成长有关。     

后处理对铝电解电容器阳极箔比容的影响

采用硫酸-盐酸体系环保型铝电解电容器用阳极箔腐蚀工艺,硝酸溶液作后处理液,结合SEM分析,探讨了硝酸后处理在阳极箔表面的清洗机理,研究了直流电侵蚀后,硝酸后处理对阳极箔比容的影响。结果表明:在硝酸溶液温度为65℃、清洗时间为250 s的条件下,阳极箔比容随着硝酸质量浓度的增加而增加,当硝酸质量浓度增至35 g/L时,阳极箔比容达到最大值0.70×10–6 F/cm2。硝酸质量浓度继续增加,阳极箔比容逐渐减小。最佳后处理参数为:硝酸质量浓度为35 g/L,处理温度为65℃,清洗时间为250 s。     

缓蚀剂在高压阳极箔电解扩孔中的作用机理

将高压阳极发孔铝箔在70℃、质量分数为3%的硝酸液中阳极电解扩孔,研究了添加大分子缓蚀剂聚苯乙烯磺酸(PSSA)后高压阳极箔的腐蚀机理。结果显示:添加PSSA后,腐蚀箔减薄量明显降低,质量损失率减小,并孔率降低,520 V化成的比容提高了约23%。隧道孔由孔口大、孔内小的"锥子"状转变为孔口小、孔内大的"垒球棒"状。铝箔表面的电位显著上升,而隧道孔内的电位基本保持不变,从而证明了,大分子缓蚀剂PSSA提高了铝箔表面和隧道孔口附近的电化学反应的阻力,电流主要分布到孔内,加速了孔内的扩孔过程。     

A magnetised foil as inclined π-flipper for time-of-flight neutron beams

A prototype instrument with an inclined ferromagnetic foil was built which was capable of π-flipping over a broad wavelength range of polarised thermal neutrons in a time-of-flight beam. It was found that, for a single foil, polarised neutrons could be flipped in a wavelength range of 0.2-0.5 nm with an efficiency of 93%. With improved mechanical setup this range probably can even be extended to 0.1-1.0 nm. Foil flippers can have some major advantages for polychromatic SESANS over resonance flippers, but the technical realisation with four foils in series will be challenging.